1. Field of the Invention
The invention relates to a brush, particularly a brush for applying a cosmetic product to keratinous fibers, especially for applying mascara to the eyelashes to a dye to the hair, and to a make-up device comprising the brush; the brush has a curved core.
2. Description of the Preferred Embodiment
A brush for applying a cosmetic product customarily comprises an elongate core, formed by a helical twist of two branches of a metal wire which has been bent into a U before the branches were twisted, and bristles inserted radially into this core and gripped between these twisted branches. Such brushes may be of various shapes and have cutouts.
When these brushes are used to apply mascara to the eyelashes, such shapes and such cutouts are designed to make it possible to obtain a heavier or lighter make-up effect, with varying amounts of lengthening and of curling of the eyelashes.
Brushes in the shape of a fragment of a torus are known, these brushes being obtained by twisting the core of a cylindrical brush into an arc of a circle. Such brushes have a convex face, a concave face, and two more or less flat faces. Such brushes are not very easy to handle because, if the user twists the wand of such a brush about its axis between her fingers in order for example to apply a product to here eyelashes, she has continually to correct the distance between the brush and the eyelashes. With these brushes it is difficult to apply make-up in the corner of the eye without overspill onto the eyelid and the side of the nose. Furthermore, it has been observed that such a brush tends to coat the eyelashes without spreading out the product very much and without separating the lashes very much. Brushes obtained by twisting the core of a cylindro-conical brush into a circular arc have the same drawbacks.
It has therefore become desirable to have available brushes that allow the eyelashes to be engaged fully by the brush in order to spread out the product correctly and to separate the lashes properly. Another object of the invention is to provide a brush which is still simple and economical to apply, and is practical to use.
The Applicant has unexpectedly discovered novel brushes for applying a cosmetic product which, when used to apply mascara to the eyelashes, make it possible to obtain a make-up effect with a great deal of separation, curling and lengthening and with a product spread out along the entire length of the lash. These brushes are moreover very easy to handle and allow make-up to be applied with ease to the corner of the eye.
A first aspect of the invention provides a brush comprising a wand defining a major axis (Xxe2x80x94X); a core comprising a first end and a second end, the first end being secured to the wand: bristles inserted radially into this core, the ends of the bristles defining an envelope surface of the brush, this envelope surface having a first end and a second end, the brush being characterized in that the core describes a curve (C) in a plane of curvature (P); and in that the envelope surface of the brush, over at least part of its length, has a cross section of elongate shape in the direction of an axis (Zxe2x80x94Z) of greatest length parallel to the plane of curvature (P).
The cross section of the envelope surface is intended to mean a section through the envelope surface on a plane perpendicular to the core.
Preferably, the curve (C) is more or less circular. That side of the brush which is in the concave part of the curve (C) forms a first comb-line part. That side of the brush which is on the opposite side likewise forms a second comb-like part.
As the cross sections of the envelope surface of the brush are elongate in the direction of the axis of greatest length, in the direction parallel to the plane (P) of twisting of the core, the brush according to the invention has two broad flattened faces.
The first comb-like part, that is in the hollow of the brush, is very close in shape to the contour of the eyelashes. Furthermore, it contains long and therefore very flexible bristles, and these bristles converge. It can therefore engage the eyelashes along the entire width of the eyelid, lengthen them and curl them. As this comb-like part has a high density of bristles, it encourages the curling of the lash. The second comb-like part on the opposite side has less dense and more spaced cut bristles since they diverge. This second comb-like part can therefore comb the lashes more easily and spread the product over their entire length. The two comb-like parts are narrow compared with the faces of the brush. They can therefore penetrate well into the lashes in order to separate them over their entire length.
As the distance between the two faces is shorter than the width of the brush, the brush can slip easily into the corner of the eye to apply make-up to the eyelashes without overspill around the corner of the eye.
The two wide faces of the brush which have bristles which are shorter, and therefore less flexible than the bristles of the sides, allow very effective application of the product to the lashes.
The very pronounced and markedly differing characteristics of the faces and of the sides give this brush a surprising dynamic behavior when the user turns the brush between her fingers, the lashes are alternately coated and curled then combed out with uncustomary intensity.
Preferably the core is central with respect to each cross section.
In a first alternative form of the invention, provision may be made for the cross section to have at least two sides in the direction of the axis (Zxe2x80x94Z) of greatest length, these sides being more or less parallel to the axis (Zxe2x80x94Z).
In a second alternative form of the invention, provision may be made for the cross section to have at least two sides in the direction of the axis (Zxe2x80x94Z) of greatest length, these sides having a convex shape. According to this alternative form, provision may be made for the sides of the cross section to have two ends, the width of the section in the direction of the axis (Yxe2x80x94Y) perpendicular to the axis (Zxe2x80x94Z) of greatest length at one of these ends, or at both of these ends, being more or less zero.
With either of the alternative forms of the invention, it is preferable for the cross section to have at least two sides in the direction of the axis (Yxe2x80x94Y), this axis being perpendicular to the axis (Zxe2x80x94Z) of greatest length, these sides having a convex shape.
Advantageously, the cross section has a maximum width (D) in the direction of the axis (Zxe2x80x94Z) of greatest length and a maximum width (d) in the direction of the axis (Yxe2x80x94Y), D and d satisfying the relationship.
D greater than 1.5d
More preferably still, D and d satisfy the relationship:
D greater than 2d
The longer length can vary along the core. In order that the make-up characteristics described hereinabove are more pronounced, brushes are preferred in which the envelope surface has an elongate cross section over at least 50% and preferably at least 75% of its length.
Advantageously, the brushes according to the invention are designed in such a way that, for each cross section, the axis of greatest length and the axis of greatest width are perpendicular.
For greater ease of handling, the ends of the core are preferably aligned with the axis Xxe2x80x94X.
A second aspect of the invention is a method of manufacturing a brush as described hereinabove, the method being characterized in that it comprises the following steps:
(i) producing a starting brush comprising a wand defining a major axis (Xxe2x80x94X); and a core comprising a first end and a second end, the first end being secured to this wand, the core being straight and aligned with the wand, bristles being inserted radially into this core, the end of the bristles defining an envelope surface of the starting brush.
(ii) trimming the bristles of the starting brush in such a way that the envelope surface of the brush over at least part of its length has a cross section of elongate shape in the direction of an axis (Zxe2x80x94Z) of greatest length, and
(iii) giving the core a main twist in the plane parallel to the axis (Zxe2x80x94Z) of greatest length and passing through the wand.
Preferably, in a fourth step;
(iv) a secondary twist is given to that end of the core which is secured to the wand in order to align the second end of the core with the main axis (Xxe2x80x94X).
More preferably, steps (i) and (ii) are carried out in such a way that the core is central with respect to the faces of the straight trimmed brush.
Advantageously, the starting brush is trimmed in such a way that the envelope surface has an elongate cross section over at least 50% and preferably at least 75%, of its length.
In a preferred embodiment of the invention, step (iii) is carried out in such a way as to give the core a main twist which is more or less an arc of a circle.
Furthermore, the bristles of the brushes according to the invention may be of any kind: the bristles may be of different lengths, of different diameters or of different cross-sections, or of different materials; the bristles may have tapered ends or forked ends, or be shaped like a hairpin, or may have undergone any sort of treatment known to those skilled in the art.
The brush according to the invention may contain alternating rows of short bristles and of long bristles, only the long bristles being involved in defining the envelope surface of the brush. This alternative form of the brush of the invention makes it possible to accentuate the coating of the eyelash with product.
The starting brush may have been milled before being subjected to the method of the invention, in such a way that it has long scattered bristles which are not taken into account in defining the envelope surface of the starting brush.
The helical twisting of the two branches of metal wire that forms the core may be with a right-hand twist as is customary in the manufacture of make-up brushes, or with a left-hand twist, as per the teachings of FR-A-2701198. To manufacture a brush with a left-hand twist, the branches of the core are twisted by turning to the left to form turns that turn in the clockwise direction about the core in a direction from the wand towards the end of the brush.
A third aspect of the invention provides a make-up device comprising: a mascara reservoir and a mascara-applicator member according to the first aspect.
Owing to its special shape, when the brush passes through a wringing device, its sides are very well wrung out while its faces are wrung out to a lesser extent. In particular, the sides and the faces are wrung asymmetrically on account of their curvature. This special feature allows the user, depending on which of the faces is used, to apply make-up with a heaviness and intensity that can vary along the entire length of the eyelid.
The flexibility of the bristles, and the flexibility of the core, can be altered to encourage or discourage the wringing-out of the brush.
In order to make the subject-matter of the invention easier to understand, several brushes that have the characteristics of this invention will be described hereafter by way of example.